Re: [PATCH net-next v7 1/7] net: introduce rstreason to detect why the RST is sent

2024-04-23 Thread Jason Xing
On Tue, Apr 23, 2024 at 7:57 PM Simon Horman  wrote:
>
> On Tue, Apr 23, 2024 at 10:17:31AM +0800, Jason Xing wrote:
> > On Tue, Apr 23, 2024 at 10:14 AM Jason Xing  
> > wrote:
> > >
> > > Hi Simon,
> > >
> > > On Tue, Apr 23, 2024 at 2:28 AM Simon Horman  wrote:
> > > >
> > > > On Mon, Apr 22, 2024 at 11:01:03AM +0800, Jason Xing wrote:
> > > >
> > > > ...
> > > >
> > > > > diff --git a/include/net/rstreason.h b/include/net/rstreason.h
> > > >
> > > > ...
> > > >
> > > > > +/**
> > > > > + * There are three parts in order:
> > > > > + * 1) reset reason in MPTCP: only for MPTCP use
> > > > > + * 2) skb drop reason: relying on drop reasons for such as passive 
> > > > > reset
> > > > > + * 3) independent reset reason: such as active reset reasons
> > > > > + */
> > > >
> > > > Hi Jason,
> > > >
> > > > A minor nit from my side.
> > > >
> > > > '/**' denotes the beginning of a Kernel doc,
> > > > but other than that, this comment is not a Kernel doc.
> > > >
> > > > FWIIW, I would suggest providing a proper Kernel doc for enum 
> > > > sk_rst_reason.
> > > > But another option would be to simply make this a normal comment,
> > > > starting with "/* There are"
> > >
> > > Thanks Simon. I'm trying to use the kdoc way to make it right :)
> > >
> > > How about this one:
> > > /**
> > >  * enum sk_rst_reason - the reasons of socket reset
> > >  *
> > >  * The reason of skb drop, which is used in DCCP/TCP/MPTCP protocols.
> >
> > s/skb drop/sk reset/
> >
> > Sorry, I cannot withdraw my previous email in time.
> >
> > >  *
> > >  * There are three parts in order:
> > >  * 1) skb drop reasons: relying on drop reasons for such as passive
> > > reset
> > >  * 2) independent reset reasons: such as active reset reasons
> > >  * 3) reset reasons in MPTCP: only for MPTCP use
> > >  */
> > > ?
> > >
> > > I chose to mimic what enum skb_drop_reason does in the
> > > include/net/dropreason-core.h file.
> > >
> > > > +enum sk_rst_reason {
> > > > +   /**
> > > > +* Copy from include/uapi/linux/mptcp.h.
> > > > +* These reset fields will not be changed since they adhere to
> > > > +* RFC 8684. So do not touch them. I'm going to list each 
> > > > definition
> > > > +* of them respectively.
> > > > +*/
> > >
> > > Thanks to you, I found another similar point where I smell something
> > > wrong as in the above code. I'm going to replace '/**' with '/*' since
> > > it's only a comment, not a kdoc.
>
> Likewise, thanks Jason.
>
> I haven't had time to look at v8 properly,
> but I see that kernel-doc is happy with the changed
> you have made there as discussed above.
>

Thank you, Simon. I learned something new about the coding style.

Besides, some other nit problems have been spotted by Matt. I will fix
them if it's required to send a new version.



Re: [PATCH net-next v7 1/7] net: introduce rstreason to detect why the RST is sent

2024-04-23 Thread Simon Horman
On Tue, Apr 23, 2024 at 10:17:31AM +0800, Jason Xing wrote:
> On Tue, Apr 23, 2024 at 10:14 AM Jason Xing  wrote:
> >
> > Hi Simon,
> >
> > On Tue, Apr 23, 2024 at 2:28 AM Simon Horman  wrote:
> > >
> > > On Mon, Apr 22, 2024 at 11:01:03AM +0800, Jason Xing wrote:
> > >
> > > ...
> > >
> > > > diff --git a/include/net/rstreason.h b/include/net/rstreason.h
> > >
> > > ...
> > >
> > > > +/**
> > > > + * There are three parts in order:
> > > > + * 1) reset reason in MPTCP: only for MPTCP use
> > > > + * 2) skb drop reason: relying on drop reasons for such as passive 
> > > > reset
> > > > + * 3) independent reset reason: such as active reset reasons
> > > > + */
> > >
> > > Hi Jason,
> > >
> > > A minor nit from my side.
> > >
> > > '/**' denotes the beginning of a Kernel doc,
> > > but other than that, this comment is not a Kernel doc.
> > >
> > > FWIIW, I would suggest providing a proper Kernel doc for enum 
> > > sk_rst_reason.
> > > But another option would be to simply make this a normal comment,
> > > starting with "/* There are"
> >
> > Thanks Simon. I'm trying to use the kdoc way to make it right :)
> >
> > How about this one:
> > /**
> >  * enum sk_rst_reason - the reasons of socket reset
> >  *
> >  * The reason of skb drop, which is used in DCCP/TCP/MPTCP protocols.
> 
> s/skb drop/sk reset/
> 
> Sorry, I cannot withdraw my previous email in time.
> 
> >  *
> >  * There are three parts in order:
> >  * 1) skb drop reasons: relying on drop reasons for such as passive
> > reset
> >  * 2) independent reset reasons: such as active reset reasons
> >  * 3) reset reasons in MPTCP: only for MPTCP use
> >  */
> > ?
> >
> > I chose to mimic what enum skb_drop_reason does in the
> > include/net/dropreason-core.h file.
> >
> > > +enum sk_rst_reason {
> > > +   /**
> > > +* Copy from include/uapi/linux/mptcp.h.
> > > +* These reset fields will not be changed since they adhere to
> > > +* RFC 8684. So do not touch them. I'm going to list each 
> > > definition
> > > +* of them respectively.
> > > +*/
> >
> > Thanks to you, I found another similar point where I smell something
> > wrong as in the above code. I'm going to replace '/**' with '/*' since
> > it's only a comment, not a kdoc.

Likewise, thanks Jason.

I haven't had time to look at v8 properly,
but I see that kernel-doc is happy with the changed
you have made there as discussed above.




Re: [PATCH net-next v7 1/7] net: introduce rstreason to detect why the RST is sent

2024-04-22 Thread Jason Xing
On Tue, Apr 23, 2024 at 10:14 AM Jason Xing  wrote:
>
> Hi Simon,
>
> On Tue, Apr 23, 2024 at 2:28 AM Simon Horman  wrote:
> >
> > On Mon, Apr 22, 2024 at 11:01:03AM +0800, Jason Xing wrote:
> >
> > ...
> >
> > > diff --git a/include/net/rstreason.h b/include/net/rstreason.h
> >
> > ...
> >
> > > +/**
> > > + * There are three parts in order:
> > > + * 1) reset reason in MPTCP: only for MPTCP use
> > > + * 2) skb drop reason: relying on drop reasons for such as passive reset
> > > + * 3) independent reset reason: such as active reset reasons
> > > + */
> >
> > Hi Jason,
> >
> > A minor nit from my side.
> >
> > '/**' denotes the beginning of a Kernel doc,
> > but other than that, this comment is not a Kernel doc.
> >
> > FWIIW, I would suggest providing a proper Kernel doc for enum sk_rst_reason.
> > But another option would be to simply make this a normal comment,
> > starting with "/* There are"
>
> Thanks Simon. I'm trying to use the kdoc way to make it right :)
>
> How about this one:
> /**
>  * enum sk_rst_reason - the reasons of socket reset
>  *
>  * The reason of skb drop, which is used in DCCP/TCP/MPTCP protocols.

s/skb drop/sk reset/

Sorry, I cannot withdraw my previous email in time.

>  *
>  * There are three parts in order:
>  * 1) skb drop reasons: relying on drop reasons for such as passive
> reset
>  * 2) independent reset reasons: such as active reset reasons
>  * 3) reset reasons in MPTCP: only for MPTCP use
>  */
> ?
>
> I chose to mimic what enum skb_drop_reason does in the
> include/net/dropreason-core.h file.
>
> > +enum sk_rst_reason {
> > +   /**
> > +* Copy from include/uapi/linux/mptcp.h.
> > +* These reset fields will not be changed since they adhere to
> > +* RFC 8684. So do not touch them. I'm going to list each definition
> > +* of them respectively.
> > +*/
>
> Thanks to you, I found another similar point where I smell something
> wrong as in the above code. I'm going to replace '/**' with '/*' since
> it's only a comment, not a kdoc.
>
> Thanks,
> Jason



Re: [PATCH net-next v7 1/7] net: introduce rstreason to detect why the RST is sent

2024-04-22 Thread Jason Xing
Hi Simon,

On Tue, Apr 23, 2024 at 2:28 AM Simon Horman  wrote:
>
> On Mon, Apr 22, 2024 at 11:01:03AM +0800, Jason Xing wrote:
>
> ...
>
> > diff --git a/include/net/rstreason.h b/include/net/rstreason.h
>
> ...
>
> > +/**
> > + * There are three parts in order:
> > + * 1) reset reason in MPTCP: only for MPTCP use
> > + * 2) skb drop reason: relying on drop reasons for such as passive reset
> > + * 3) independent reset reason: such as active reset reasons
> > + */
>
> Hi Jason,
>
> A minor nit from my side.
>
> '/**' denotes the beginning of a Kernel doc,
> but other than that, this comment is not a Kernel doc.
>
> FWIIW, I would suggest providing a proper Kernel doc for enum sk_rst_reason.
> But another option would be to simply make this a normal comment,
> starting with "/* There are"

Thanks Simon. I'm trying to use the kdoc way to make it right :)

How about this one:
/**
 * enum sk_rst_reason - the reasons of socket reset
 *
 * The reason of skb drop, which is used in DCCP/TCP/MPTCP protocols.
 *
 * There are three parts in order:
 * 1) skb drop reasons: relying on drop reasons for such as passive
reset
 * 2) independent reset reasons: such as active reset reasons
 * 3) reset reasons in MPTCP: only for MPTCP use
 */
?

I chose to mimic what enum skb_drop_reason does in the
include/net/dropreason-core.h file.

> +enum sk_rst_reason {
> +   /**
> +* Copy from include/uapi/linux/mptcp.h.
> +* These reset fields will not be changed since they adhere to
> +* RFC 8684. So do not touch them. I'm going to list each definition
> +* of them respectively.
> +*/

Thanks to you, I found another similar point where I smell something
wrong as in the above code. I'm going to replace '/**' with '/*' since
it's only a comment, not a kdoc.

Thanks,
Jason



Re: [PATCH net-next v7 1/7] net: introduce rstreason to detect why the RST is sent

2024-04-22 Thread Simon Horman
On Mon, Apr 22, 2024 at 11:01:03AM +0800, Jason Xing wrote:

...

> diff --git a/include/net/rstreason.h b/include/net/rstreason.h

...

> +/**
> + * There are three parts in order:
> + * 1) reset reason in MPTCP: only for MPTCP use
> + * 2) skb drop reason: relying on drop reasons for such as passive reset
> + * 3) independent reset reason: such as active reset reasons
> + */

Hi Jason,

A minor nit from my side.

'/**' denotes the beginning of a Kernel doc,
but other than that, this comment is not a Kernel doc.

FWIIW, I would suggest providing a proper Kernel doc for enum sk_rst_reason.
But another option would be to simply make this a normal comment,
starting with "/* There are"

> +enum sk_rst_reason {

...



Re: [PATCH net-next v7 1/7] net: introduce rstreason to detect why the RST is sent

2024-04-22 Thread Matthieu Baerts
On 22/04/2024 11:17, Jason Xing wrote:> On Mon, Apr 22, 2024 at 4:47 PM
Matthieu Baerts  wrote:
>> On 22/04/2024 05:01, Jason Xing wrote:
>>> From: Jason Xing 

(...)

>>> diff --git a/include/net/rstreason.h b/include/net/rstreason.h
>>> new file mode 100644
>>> index ..c57bc5413c17
>>> --- /dev/null
>>> +++ b/include/net/rstreason.h
>>> @@ -0,0 +1,144 @@
>>> +/* SPDX-License-Identifier: GPL-2.0-or-later */
>>> +
>>> +#ifndef _LINUX_RSTREASON_H
>>> +#define _LINUX_RSTREASON_H
>>> +#include 
>>> +#include 
>>> +
>>> +#define DEFINE_RST_REASON(FN, FNe)   \
>>> + FN(MPTCP_RST_EUNSPEC)   \
>>> + FN(MPTCP_RST_EMPTCP)\
>>> + FN(MPTCP_RST_ERESOURCE) \
>>> + FN(MPTCP_RST_EPROHIBIT) \
>>> + FN(MPTCP_RST_EWQ2BIG)   \
>>> + FN(MPTCP_RST_EBADPERF)  \
>>> + FN(MPTCP_RST_EMIDDLEBOX)\
>>
>> Small detail: should it not make more sense to put the ones linked to
>> MPTCP at the end? I mean I guess MPTCP should be treated in second
>> priority: CONFIG_MPTCP could not be set, and the ones linked to TCP
>> should be more frequent, etc.
> 
> Do you mean that I need to adjust the order: 1) tcp reasons first, 2)
> independent reasons, 3) mptcp reasons ?

Correct, it looks like it is a more "natural" order.

> Reasonable. I will do it :)

Thanks!

Cheers,
Matt
-- 
Sponsored by the NGI0 Core fund.




Re: [PATCH net-next v7 1/7] net: introduce rstreason to detect why the RST is sent

2024-04-22 Thread Jason Xing
Hello Matthieu,

On Mon, Apr 22, 2024 at 4:47 PM Matthieu Baerts  wrote:
>
> Hi Jason,
>
> On 22/04/2024 05:01, Jason Xing wrote:
> > From: Jason Xing 
> >
> > Add a new standalone file for the easy future extension to support
> > both active reset and passive reset in the TCP/DCCP/MPTCP protocols.
>
> Thank you for looking at that!

Thanks for the review!

>
> (...)
>
> > diff --git a/include/net/rstreason.h b/include/net/rstreason.h
> > new file mode 100644
> > index ..c57bc5413c17
> > --- /dev/null
> > +++ b/include/net/rstreason.h
> > @@ -0,0 +1,144 @@
> > +/* SPDX-License-Identifier: GPL-2.0-or-later */
> > +
> > +#ifndef _LINUX_RSTREASON_H
> > +#define _LINUX_RSTREASON_H
> > +#include 
> > +#include 
> > +
> > +#define DEFINE_RST_REASON(FN, FNe)   \
> > + FN(MPTCP_RST_EUNSPEC)   \
> > + FN(MPTCP_RST_EMPTCP)\
> > + FN(MPTCP_RST_ERESOURCE) \
> > + FN(MPTCP_RST_EPROHIBIT) \
> > + FN(MPTCP_RST_EWQ2BIG)   \
> > + FN(MPTCP_RST_EBADPERF)  \
> > + FN(MPTCP_RST_EMIDDLEBOX)\
>
> Small detail: should it not make more sense to put the ones linked to
> MPTCP at the end? I mean I guess MPTCP should be treated in second
> priority: CONFIG_MPTCP could not be set, and the ones linked to TCP
> should be more frequent, etc.

Do you mean that I need to adjust the order: 1) tcp reasons first, 2)
independent reasons, 3) mptcp reasons ?

Reasonable. I will do it :)

>
> > + FN(NOT_SPECIFIED)   \
> > + FN(NO_SOCKET)   \
> > + FNe(MAX)
>
> (...)
>
> > +/* Convert reset reasons in MPTCP to our own enum type */
> > +static inline enum sk_rst_reason convert_mptcpreason(u32 reason)
> > +{
> > + switch (reason) {
> > + case MPTCP_RST_EUNSPEC:
> > + return SK_RST_REASON_MPTCP_RST_EUNSPEC;
> > + case MPTCP_RST_EMPTCP:
> > + return SK_RST_REASON_MPTCP_RST_EMPTCP;
> > + case MPTCP_RST_ERESOURCE:
> > + return SK_RST_REASON_MPTCP_RST_ERESOURCE;
> > + case MPTCP_RST_EPROHIBIT:
> > + return SK_RST_REASON_MPTCP_RST_EPROHIBIT;
> > + case MPTCP_RST_EWQ2BIG:
> > + return SK_RST_REASON_MPTCP_RST_EWQ2BIG;
> > + case MPTCP_RST_EBADPERF:
> > + return SK_RST_REASON_MPTCP_RST_EBADPERF;
> > + case MPTCP_RST_EMIDDLEBOX:
> > + return SK_RST_REASON_MPTCP_RST_EMIDDLEBOX;
> > + default:
> > + /**
> > +  * It should not happen, or else errors may occur
> > +  * in MPTCP layer
> > +  */
> > + return SK_RST_REASON_ERROR;
> > + }
> > +}
>
> If this helper is only used on MPTCP, maybe better to move it to
> net/mptcp/protocol.h (and to patch 5/7?)? We tried to isolate MPTCP code.

Roger that. I will move the helper into protocol.h as well as the patch itself.

>
> Also, maybe it is just me, but I'm not a big fan of the helper name:
> convert_mptcpreason() (same for the "drop" one). I think it should at
> least mention its "origin" (rst reason): e.g. something like
> (sk_)rst_reason_convert_mptcp or (sk_)rst_convert_mptcp_reason() (or
> mptcp_to_rst_reason())?
>
> And (sk_)rst_reason_convert_(skb_)drop() (or skb_drop_to_rst_reason())?

I agree with you. Actually I had a local patch where I used
sk_rst_reason_skbdrop() and sk_rst_reason_mptcpreason().
Interestingly, I changed them in this patch series due to the function
name being too long (which is my initial thought).

I will use sk_rst_convert_xxx_reason() as you suggested.

>
> > +/* Convert reset reasons in MPTCP to our own enum type */
>
> I don't think this part is linked to MPTCP, right?

Ah, copy-paste syndrome... Sorry, I will correct it.

>
> > +static inline enum sk_rst_reason convert_dropreason(enum skb_drop_reason 
> > reason)
> > +{
> > + switch (reason) {
> > + case SKB_DROP_REASON_NOT_SPECIFIED:
> > + return SK_RST_REASON_NOT_SPECIFIED;
> > + case SKB_DROP_REASON_NO_SOCKET:
> > + return SK_RST_REASON_NO_SOCKET;
> > + default:
> > + /* If we don't have our own corresponding reason */
> > + return SK_RST_REASON_NOT_SPECIFIED;
> > + }
> > +}
>
> (This helper could be introduced in patch 4/7 because it is not used
> before, but I'm fine either ways.)

Good. It makes more sense.

Thanks,
Jason



Re: [PATCH net-next v7 1/7] net: introduce rstreason to detect why the RST is sent

2024-04-22 Thread Matthieu Baerts
Hi Jason,

On 22/04/2024 05:01, Jason Xing wrote:
> From: Jason Xing 
> 
> Add a new standalone file for the easy future extension to support
> both active reset and passive reset in the TCP/DCCP/MPTCP protocols.

Thank you for looking at that!

(...)

> diff --git a/include/net/rstreason.h b/include/net/rstreason.h
> new file mode 100644
> index ..c57bc5413c17
> --- /dev/null
> +++ b/include/net/rstreason.h
> @@ -0,0 +1,144 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +
> +#ifndef _LINUX_RSTREASON_H
> +#define _LINUX_RSTREASON_H
> +#include 
> +#include 
> +
> +#define DEFINE_RST_REASON(FN, FNe)   \
> + FN(MPTCP_RST_EUNSPEC)   \
> + FN(MPTCP_RST_EMPTCP)\
> + FN(MPTCP_RST_ERESOURCE) \
> + FN(MPTCP_RST_EPROHIBIT) \
> + FN(MPTCP_RST_EWQ2BIG)   \
> + FN(MPTCP_RST_EBADPERF)  \
> + FN(MPTCP_RST_EMIDDLEBOX)\

Small detail: should it not make more sense to put the ones linked to
MPTCP at the end? I mean I guess MPTCP should be treated in second
priority: CONFIG_MPTCP could not be set, and the ones linked to TCP
should be more frequent, etc.

> + FN(NOT_SPECIFIED)   \
> + FN(NO_SOCKET)   \
> + FNe(MAX)

(...)

> +/* Convert reset reasons in MPTCP to our own enum type */
> +static inline enum sk_rst_reason convert_mptcpreason(u32 reason)
> +{
> + switch (reason) {
> + case MPTCP_RST_EUNSPEC:
> + return SK_RST_REASON_MPTCP_RST_EUNSPEC;
> + case MPTCP_RST_EMPTCP:
> + return SK_RST_REASON_MPTCP_RST_EMPTCP;
> + case MPTCP_RST_ERESOURCE:
> + return SK_RST_REASON_MPTCP_RST_ERESOURCE;
> + case MPTCP_RST_EPROHIBIT:
> + return SK_RST_REASON_MPTCP_RST_EPROHIBIT;
> + case MPTCP_RST_EWQ2BIG:
> + return SK_RST_REASON_MPTCP_RST_EWQ2BIG;
> + case MPTCP_RST_EBADPERF:
> + return SK_RST_REASON_MPTCP_RST_EBADPERF;
> + case MPTCP_RST_EMIDDLEBOX:
> + return SK_RST_REASON_MPTCP_RST_EMIDDLEBOX;
> + default:
> + /**
> +  * It should not happen, or else errors may occur
> +  * in MPTCP layer
> +  */
> + return SK_RST_REASON_ERROR;
> + }
> +}

If this helper is only used on MPTCP, maybe better to move it to
net/mptcp/protocol.h (and to patch 5/7?)? We tried to isolate MPTCP code.

Also, maybe it is just me, but I'm not a big fan of the helper name:
convert_mptcpreason() (same for the "drop" one). I think it should at
least mention its "origin" (rst reason): e.g. something like
(sk_)rst_reason_convert_mptcp or (sk_)rst_convert_mptcp_reason() (or
mptcp_to_rst_reason())?

And (sk_)rst_reason_convert_(skb_)drop() (or skb_drop_to_rst_reason())?

> +/* Convert reset reasons in MPTCP to our own enum type */

I don't think this part is linked to MPTCP, right?

> +static inline enum sk_rst_reason convert_dropreason(enum skb_drop_reason 
> reason)
> +{
> + switch (reason) {
> + case SKB_DROP_REASON_NOT_SPECIFIED:
> + return SK_RST_REASON_NOT_SPECIFIED;
> + case SKB_DROP_REASON_NO_SOCKET:
> + return SK_RST_REASON_NO_SOCKET;
> + default:
> + /* If we don't have our own corresponding reason */
> + return SK_RST_REASON_NOT_SPECIFIED;
> + }
> +}

(This helper could be introduced in patch 4/7 because it is not used
before, but I'm fine either ways.)

> +#endif

Cheers,
Matt
-- 
Sponsored by the NGI0 Core fund.